1. Technical Field
This application relates generally to a power converter equipped with a semiconductor module in which semiconductor devices are fabricated and a capacitor working to smooth the voltage applied to the semiconductor module.
2. Background Art
FIGS. 11 to 13 illustrates a conventional power converter 9, as taught in Japanese Patent First Publication No. 2009-5462, which works to perform power conversion between DC power and AC power. The power converter 9 consists of a plurality of semiconductor modules 92 in which semiconductor devices are installed. Each of the semiconductor modules 92 includes power terminals 920. The semiconductor modules 92 and cooling pipes 98 for cooling the semiconductor modules 92 are laid to overlap each other to form a semiconductor stack 910. The semiconductor stack 910 is disposed in a casing 96 together with other parts.
The power terminals 920 are coupled to bus bars 93 which are made up of a positive bus bar 93a, a negative bus bar 93b, and an ac bus bar 93c. Specifically, the positive bus bar 93a is connected to a positive electrode of a dc power supply (not shown). The negative bus bar 93b is connected to a negative electrode of the dc power supply. The ac bus bar 93c is joined to an ac load. The ac bus bar 93c has terminals 939, as illustrated in FIG. 13, mounted on output terminal tables 913.
The power converter 9 is, as illustrated in FIGS. 11 and 12, also equipped with a capacitor 94. The capacitor 94 works to has two bus bar connector terminals 940 and two input terminals 941. The bus bar connector terminals 940 are coupled to the positive bus bar 93a and the negative bus bar 93b, respectively. The input terminals 941 are coupled to the dc power supply. The capacitor 94 works to smooth a dc voltage applied to the positive bus bar 93a and the negative bus bar 93b. The capacitor 94 is located adjacent the semiconductor stack 910 in a direction (i.e., a Z-direction in FIGS. 11 and 12) in which the power terminals 920 extend.
The capacitor 94 has input terminals 941 to which connecting members 99 are joined for connection to the dc power supply. The connecting members 99 have ends 990 mounted on input terminal tables 912. Connector terminals (not shown) of the dc power supply are laid on and joined to the ends 990 using bolts (not shown). The bolts are inserted into the casing 96 through an opening 960. The input terminal tables 912 is disposed close to the opening 960 for facilitating the ease with which the bolts are fastened into the input terminal tables 912.
The power converter 9, however, faces the following drawback. The input terminal tables 912 are disposed away from the capacitor 94 in the Z-direction, thus resulting in need for increasing the length of the connecting members 99 in the Z-direction, which leads to increase in amount of metal material used in making the connecting members 99 and in production cost of the power converter 9.
The increase in length of the connecting members 99 also results in an increase in space in the casing 96 occupied thereby, thus increasing the overall size of the power converter 9.